Radiographic clinometer



I. M. GREENBERG RADIOGRAPHIC CLINOMETER Aug, 18, 1953 3 Sheets-Sheet 1 Filed Nov. 20, 1951 INVENTOR.

I. MELBOURNE GREENBERG BY 1 JJ fl/Qfi ATTORNE 7 g- 3 I. M. GREENBERG 2,649,548-

RADIOGR'APHIC CLINOMETER Filed Nov. 20, 1951 Y a Sheets-Sheet. 2

W53 INVENTOR.

I. MELBOURNE GREENBERG ATTORNEY Aug 1%, 1953 1. M. GREENBERG RADIOGRAPHIC CLINOMETER 3 Sheets-Sheet 3 Filed Nov. 20, 1951 INVENTOR.

LMELBOURNE GREENBERG,

ATTORNEY Patented Aug. 18, 1953 UNITED STATES PATENT OFFICE RADIOGRAPHIC CLINOMETER Irving Melbourne Greenberg, New York, N. Y.

Application November 20, 1951, Serial No. 257,342

'7 Claims. ('01. 250-67 The present invention relates to clinometers for the measurement of vertical angles, and more particularly to instruments of this type which are suitable for the radiographic registration of the measured angle of inclination directly on a photographic film simultaneously with an X-ray or other radiographic shadow.

In myelography, for example, where it is desired to determine the nature and location of a lesion within the dural sac, a heavy radio-opaque dye of oily consistency is injected into this sac within spinal column of the patient. Ordinarily, this radio-opaque dye will move freely within the dural sac. If the patient is placed in a horizontal position, the opaque dye will spread lengthwise from the point of injection. Upon displacement of the patient from a horizontal position, the opaque dye will flow longitudinally within the dural sac, and its movement may be readily observed by means of a fluoroscopic screen.

In the presence of a partial block caused by a lesion, the flow of the dye will be obstructed. The extent of the obstruction is determined by tilting the table at an increased angle. The amount of tilt required to produce a further flow of the dye beyond the obstruction is an indication of the completeness with which the dural sac is blocked. In the case of a complete block, the patient may be tilted to a nearly vertical position without further movement of the dye beyond the obstruction.

The patient usually assumes a position face downward upon the examination table, the shadow of the spinal column together with the opaque dye being observed upon a fluoroscopic screen. When an abnormality is noted, a photographic film holder is substituted in the same position as the fluoroscopic screen, and the condition is then photographically recorded. This record is meaningless for further analysis, however, unless the angular position of the patient at the time of the photograph forms a part of the permanent record.

Previously, this information was separately noted and recorded, and reference to this description was required for the interpretation of each view. The present invention records this information photographically upon the film along with view which is being radiographed, thus avoiding the necessity for preserving a separate description of the position of the patient.

In a modified form, the invention includes a glass tube containing a radio-opaque dye similar to the dye injected in the spine of the patient.

2 The tube and the dye are so arranged that a bubble indicates the angle of inclination.

In another modified form of the invention, means are provided for attaching the clinometer directly to the body of the patient for use in situations where the available radiographic facilities do not include a table which may be inclined as desired.

The invention also has application in other radiographic procedures where information regarding the magnitude of an angle is essential to the interpretation of the X-ray photograph.

Other features and advantages of the invention will become apparent upon reading the following specification together with the accompanying drawings forming a part thereof.

Referring to the drawings:

Figure l is a diagrammatic elevational view showing an embodiment of the invention as used in myelography;

Figure 2 is a side view in elevation of the embodiment shown in Figure 1;

Figure 3 is a bottom view of the device illus-.

trated in Figure 2;

Figure 4 is a side view of a modified form of the invention;

Figure 5 is a sectional view in elevation, taken along the line 55 of Figure 4, looking in the direction of the arrows;

Figure 6 is a plan view of another modification of the invention;

Figure '7 is a sectional view in elevation, taken along the line 'l-I of Figure 6, looking in the direction of the arrows;

Figure 8 is a view in elevation of another modified form of the invention;

Figure 9 is an end View of the modification shown in Figure 8;

Figure 10 is a sectional view in elevation, taken along the line Ill-ill of Figure 8, looking in the direction of the arrows;

Figure 11 is a sectional view in elevation of another modified form of the invention;

Figure 12 is an end view of the invention as shown in Figure 11;

Figure 13 is a side view in elevation of still another modified form of the invention;

Figure 14 is an end view of the embodiment shown in Figure 13;

Figure 15 is a side view illustrating the use of the embodiment of Figure 13, with the patient assuming an attitude to bring the spine into a generally vertical position; and

Figure 16 shows the embodiment of Figurel3 with the patient assuming an attitude to bring the spine into a position where the spine is inclined from the vertical.

Referring to Fig. l, a patient H is shown lying face downward on an examination table l2. A source of penetrative radiations, indicated diagrammatically as an X-ray tube i3 is shown disposed beneath the table [2, the rays passing upwardly and through the spinal column M of patient I I to produce aradiographic shadow upon the photographic film contained within the holder l5.

Film holder 15 is supported by conventional means (not shown) so that it may be moved about in a plane parallel to tablelZ at an ad'- justably fixed distance from the table I2. The supporting means also permits convenient interchangeability between the film holder and a fluoroscopic screen.

Table I2 is pivotally mounted in further'dohventional supporting means (not shown) so that it may be tilted to any desired angle up to "ninety degrees in either direction from the horizontal.

The clinometer of the present invention, desig- 'nated generally as P8, is shown mounted 'in a fixed position beneath and in close proximity to the film holder 15. As table I2 and film holder l5 are tilted together, the clinometer It will cast a shadow directly upon the which will give a permanent indication of the angle of inclination of the table I 2 at the time the X-ray view was photographed. Clinometer I6 is so positioned that its shadow will fall at the edge of the film, outside the principal picture area.

Referring to Fig. 2, the clinometer I6 is shown disposed beneath and parallel to a photographic film H, the supporting apparatus and-film holder being omitted for simplicity of illustration. X- rays passing upward-1y through clinometer l6 will cast a shadow upon film 11.

Clinometer It consists of a radib trans'pa-rent supporting plate 1-8 from which extend downwardly a pair of spaced parallel radio-transparent side members 19, of substantially semi-circular shape. The side members l9 are fi'oin'ed at their outer "edges by a relatively thin curved strip 200 of radio-transparent material, thus "forming a semi' circula'r -radio'-transparent box 30.

Confined within the radio-transparent box 30 is a radio-opaque ball 2| whichwill travel along the inner surface of curved strip 20 in accordance with the tilting of table I'2.

At the lowermost portion of curved strip 20, and afiixed to the external surface thereoif, is a radio-opaque numeral zero. When table I2 is horizontal, ball 21 will rest directly above the numeral zero, and its "shadow appearing this position will indicate the horizontal condition of table l2. Disposed on either side "of the zero mark are further radio-opaque numerals to indicate 30, '60 and '90 degree displacements from the horizontal. In order to provide for clear legibility, the sixty-degree opaque numerals are mounted on radiotran's'parent brackets 22, which support these numerals in "a plane parallel to the plane of film H. The ninety-degree numerals are mounted (in supporting plate [8. Intermediate indications "may be provided, where desired, by radio-opaque bars 23 afiixe'cl to the external -surface of strip 20. The thirty-degree opaque nuinerals are sufficiently parallel to'film '11 so that no supporting brackets will ordinarilybe required.

Since the X-ray illumination is -alwaysfroin substantially the same direction, the opaque 'numerals and intermedi'at'e indications may be so positioned by suitable radio"-=transparent supports, that a substantially linear shadow scale will be produced, and the values of intermediate angles may be readily and accurately interpolated by the position of the shadow of ball 2| as it appears in the radiographic View.

In Fig. 4, a modification of the invention is illustrated, in which the depth of physical projection of the clinometer below the film holder is appreciably reduced. In .Fig. 3, the hollow box 30 extends at angle from supporting plate I8. By reducing the extent to which the instrument extends below the film holder [5, there is less hance that the instrument may be accidentally damaged during use.

In Fig. 4, each of the opaque indicating nuiherals is "supported on a radio-transparent shelf 31, which holds the numeral in a plane parallel to the plane of film l1, thus providing a clearly iagibie shadow.

Another modified form of the invention is illustrated in Fig. 6. Instead of the ball 21, a radioopaque pointer 4| of some relatively heavy ma= terial such as lead, extends perpendicularly from a radio-transparent shaft 42 in a downward and normally outward direction. Shaft '42 is journaled at 43 in supporting plate "3 and at 44 in a transparent supporting bracket 45. Shaft M is freely rotatable aridis inclined outwardly frbm the vertical so that pointer 41 will assume an angle which, from a plan view, varies in accord ance with the angle by which table 1'2 is displaced from the horizontal. Pointer M is moved by gravity, its weight being sufficient for this purpose.

A transparent fiat substantially semicircular 3.10112/06 member 46 extends outwardly from supporting plate H5 at such an angle thati-t is par-ab lel to the plane of motion of pointer M aii'd is close proximity thereto. The angle designating numerals, or other -indi'cia, are supported on a plurality of transparent blocks or supp'e'rting members 4-! which are carried by arcuate member 3 6. The bloc-ks WI hold their refiective ahgle designating "numerals substantially parallel to the plane or film Hf, thus providing fonc lear legibilit'y of their respective shadows upon the filrn.

Fig. 8 illustrates a runner r'nddificatidn or the invention. Supporting plate 1 8 'is shown pmvi'ded with "two spaced downwardly extends-1g transparent trunniohfmembers "5'! which support a transverse shaft e2, also of transparent rn'aterial, freely rotatably journaled-theieinat 53. Centrally disposed 'on shaft 52 is a semi-hollow transparent wheel '54. The lower half of wheel We is solid,"o'r is "otherwise provided with a radiotra'nsparent weight, so thatfa fixed point "on-the periphery of wheel 5 1 will always be uppermost.

An opaque niimera'l zero is affixed to th'eexterm1 periphery of Wheel "5 5 "atfthi's uppermost point and an opaque fixed index "55 is secured "to supporting plate I 8 to register 'Withthe numeralzero when the table P2 is "in its horizontal position. Disposed about the upper "external eri hery "or wheel 54 at desired points are further "opaque indicia arranged "to indicate various angular positions or inelinationoi table T2. The indicla for one of'the two quadrants is 'iiisplacod toward one side'o'f wheel'fi' l ahdthe'indicia for the other uadrant are displaced toward the other side to avoid overlapping of their shadows and "thus insure that the 'cuno'mete'r readings will he emails; readable/even intlie nine'ty degreeTpdsi't'ioris.

As "shown in Figures '11 and '12 the clinoni'ter may comprise a "glass tube 611 :gen emuy shapes in the form of acircular arc, "which is partially filled with a radio-opaque liquid Bl to form a bubble 62 which will always assume a position at the uppermost portion of the tube 6.0.

A plurality of radio-opaque indicia 63 are disposed in suitably spaced relationship adjacent to the tube 60. Tube 60 is advantageously supported by suitable radio-transparent sup-porting means depending from the supporting plate l8 in such a position that the indicia 63 will be disposed in a plane substantially parallel to the plane of the film II. A plurality of radio-transparent supporting brackets 64 are shown by way of illustration as a convenient means of attaining the requisite parallel relationship.

Figures 13 to 16 illustrate a modified form of the invention comprising supporting means for attaching the clinometer of the invention directly to the body of the patient.

This adaptation of the invention is suitable for use where the facilities for radiological examination include the usual fluoroscope with a vertical screen but where no inclinable examination table is available,

In this modified form, the clinometer is shown as embodying the specific construction illustrated in Figures 2 and 3 described above, with the exception of the disposition of the radio-opaque indicia.

In this modified form, because the hollow semicircular box 30 is traversed horizontally by the penetrative radiations, the radio-opaque numerals, zero, 30, 60, etc., are disposed in a substantially vertical plane being laterally secured to the box 30.

Attaching means, shown by way of illustration as comprising upper and lower radio-transparent straps and II respectively permit the clinometer to be secured to the side of the patient H.

The photographic film I1 is diagrammatically shown disposed in a substantially vertical plane immediately adjacent the left side of the patient. Accordingly, the angle of inclination of the spine of the patient may be determined by noting the position of radiographic shadow of the radioopaque ball 21 upon the film ll relative to the shadows of the radio-opaque numerals.

It will be noted that in all of the embodiments of the invention described above, that errors due to parallax are minimized by placing the numeral designating the angle in close proximity to the index from which the angle is read. Furthermore, the opaque angle designating numerals are disposed in a plane substantially parallel to the plane of the film on which the reading is photographically recorded. In the embodiment of Figures 8 to 10, the particular numerals indicating the actual angle of inclination are substantially parallel to the film H. In the other embodiments, all of the numerals are substantially parallel to the film.

I have shown what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to secure by Letters Patent is the invention as defined in the appended claims.

What is claimed is:

1. In a clinometer for the radiographic recording of the indication of the magnitude of an angle upon a plane photographic medium; radioopaque indicia; a radio-opaque index, the indicia and the index being movable with respect to each other to produce a radiographic shadow from which the angle may be determined; and radiotransparent supporting means for the indicia and the index, the supporting means maintaining at least the particular portion of the indicia from which the angle is to be read in a plane substantially parallel to the plane of the photographic medium, the last-named portion of the indicia being disposed in close proximity to the index.

2. A clinometer according to claim 1, in which the supporting means comprises a hollow, substantially semi-cylindrical box, and the index is a ball confined within the box and movable about the curved portion of the interior thereof.

3. A clinometer according to claim 2 in which the indicia are radio-opaque numerals disposed in proximity to the curved outer portion of the box.

4. A clinometer for the radiographic recording of the indication of the magnitude of an angle upon a photographic medium comprising a radio-transparent support, radio opaque indicia on said support and a radio opaque index maintained in operative relation to said indicia, the indicia and the index being freely movable with respect to each other when the clinometer is tilted so as to produce a radiographic shadow relative to said indicia from which the angle of tilt may be determined.

5. A clinometer for the radiographic recording of the indication of the magnitude of an angle upon an X-ray film maintained in a film holder, said clinometer comprising a radio-transparent, semi-cylindrical support connected to and depending from the X-ray film holder, radio opaque indicia on said support and a radio opaque index maintained by said support in operative relation to said indicia, the indicia and the index being freely movable with respect to each other when the clinometer is tilted so as to produce a radiographic shadow relative to said indicia from which the angle of tilt may be determined.

6. A clinometer according to claim 5 and wherein said radio opaque indicia comprises a series of numerals, said numerals being maintained by said support in planes substantially parallel to the film holder.

7. A clinometer for the radiographic recording of the indication of the magnitude of an angle upon an X-ray film maintained in a planar film holder, said clinometer comprising a radiotransparent support connected to said film holder, a series of radio opaque numerals on said support and a radio opaque index maintained in operative relation to said series of numerals, said index being freely movable with respect to the series of numerals when the clinometer is tilted so as to produce a radiographic shadow in relation to said series of numerals from which the angle of tilt may be determined, each numeral of the series being maintained by said support in a plane substantially parallel to the planar film holder.

IRVING MELBOURNE GREENBERG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,917,433 Cressler July 11, 1933 2,496,218 Kieffer Jan. 31, 1950 

